644638 ÷ 52 
We want to figure out the number of times 644638 can be divided by 52.

On to step 1:
The number 52 fits into 6 0 times, leaving a remainder of 6.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Fetch the next digit (4) from the dividend, attach it to 6 and continue: 64 / 52

Moving on to step 2:
If we divide 64 by 52, we get 1 and a remainder of 12.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Deduct 52 from 64 and we're left with 12.
Grab the next digit (4) from the dividend, add it to 12, then carry on: 124 / 52

Step 3:
When dividing 124 by 52, we get 2 with a remainder of 20.
Put 2 as the next digit of the answer. 
Result so far: 12.0
Subtracting 104 from 124 leaves us with 20.
Fetch the next digit (6) from the dividend, attach it to 20 and continue: 206 / 52

Let's proceed to step 4:
If we divide 206 by 52, we get 3 and a remainder of 50.
Put 3 as the next digit of the answer. 
Result so far: 123.0
If we take 156 away from 206, we end up with 50.
Bring next digit (3) of the dividend behind the 50 and repeat the process: 503 / 52

Moving on to step 5:
52 goes into 503 9 times with a remainder of 35.
Record the quotient 9 as the next digit in the result. 
Result so far: 1239.0
If we subtract 468 from 503, we get 35.
Fetch the next digit (8) from the dividend, attach it to 35 and continue: 358 / 52

Step 6:
52 can be fit into 358 6 times, resulting in a remainder of 46.
Use 6 as the next digit of our solution. 
Result so far: 12396.0
Subtracting 312 from 358 leaves us with 46.
Since there are no more digits in the dividend, we add a zero to the remainder making it 460, and continue the process.

Moving on to step 7:
When dividing 460 by 52, we get 8 with a remainder of 44.
Record the quotient 8 as the next digit in the result. 
Result so far: 12396.8
Subtracting 416 from 460 leaves us with 44.
Since there are no more digits in the dividend, we add a zero to the remainder making it 440, and continue the process.

Let's proceed to step 8:
52 goes into 440 8 times with a remainder of 24.
Write down 8 as next digit of the result. 
Result so far: 12396.88
The remainder is 24 after subtracting 416 from 440.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

After the division, we end up with 12396.88 and a remainder of 0.024.